Automatic discharge regulator

ABSTRACT

An automatic discharge regulator is disclosed for a separator or classifier to regulate the discharge of solid particles conveyed in a slurry. Hydrocyclones are frequently used for separating solid particulate material from liquids, but if an open solid discharge exit is provided, the regulation of separation cannot be controlled unless there is a constant flow of solid material in the slurry. The regulator has two sheets of flexible material in side by side relationship held together at two opposing edges to form a sleeve. One end of the sleeve fits over the exit from the separator. The sleeve has reinforcing pads of flexible material which are positioned on the outside surfaces of the sheets of flexible material and keep the other end of the sleeve closed when no solid material passes therethrough. A method of regulating the discharge of solid materials from such a discharge sleeve attached to the exit spigot of a hydrocyclone is disclosed by controlling the vacuum in the hydrocyclone.

United States Patent 1191 1111 3,923,210 Jackson 1 Dec. 2, 1975AUTOMATIC DISCHARGE REGULATOR [75] Inventor: Lawrence Donald AlexanderPnmary b'mminer s tanley Tollberg Jackson, Montreal, Canada Attorney,Agent, or Firm-Larson, Taylor & Hinds [73] Assignee: Lawjack EquipmentLimited, [57] ABSTRACT Montreal Canada An automatic discharge regulatoris disclosed for a 22 il d; 21 1974 separator or classifier to regulatethe discharge of solid particles conveyed in a slurry. Hydrocyclones are[2]] Appl' NO; 444508 frequently used for separating solid particulatematerial from liquids, but if an open solid discharge exit is [30]Foreign Application priority Data provided, the regulation of separationcannot be controlled unless there is a constant flow of solid materiall' b.22. 1973 U t d K d 8807 73 e m e mg Om in the slurry. The regulatorhas two sheets of flexible [52] U S CL H 222/494 222/529 material inside by side relationship held together at [5 H Cl 2 B65D 37/00 twoopposing edges to form a sleeve. One end of the [58] Field of i i 494107 sleeve fits over the exit from the separator. The sleeve 6 hasreinforcing pads of flexible material which are positioned on theoutside surfaces of the sheets of flexi- [56] References Cited blematerial and keep the other end of the sleeve UNITED STATES PATENTSclosed when no solid material passes therethrough. A method ofregulating the discharge of solid materials 1,964,860 7/1934 Rabe ct a1222/491 X f Such a discharge Sleeve attached to the i n spigot of ahydrocyclone is disclosed by controlling urp y 3,610,477 10 1971 Herzig222/213 the Vacuum m the hydrocyclone 3,815,794 6/1974 Carlisle 222/4918 Claims, 4 Drawing Figures Sheet 1 of 2 US. Patent Dec. 2, 1975 US.Patent D'e.2,1975 sh eetzom 3,923,210

AUTOMATIC DISCHARGE REGULATOR This invention relates to hydrocycloneclassifiers or centrifugal separators and more particularly to a devicefor controlling the density of discharging particulate materialseparated from a fluid in a classifier or separator.

I-Iydrocyclones are generally used for separating solids in the form offine particulate material from liquids. They are primarily used in boththe mining'and aggregate industry. One use of a hydrocyclone is insystems where a pipe line is used for transporting solids in a liquidsuspension. In this system, solids in the form of powder or fines suchas sand, coal dust, clay, mineral ore, etc., are deposited into a pipeline having a liquid, usually water, flowing therein. The water acts asa carrier and conveys the solid particles along the pipe line. Providedvelocity of the water in the pipe line is maintained above a minimumlevel, the particles do not settle and are kept in suspension throughoutthe length of the pipe. The hydrocyclone is generally a centrifugalunit. The liquid and solid particles enter the hydrocyclone tangentiallyand are subjected to a centrifugal force which forces the coarser andhigher density material towards the outside wall of the hydrocyclone.The larger solid particles work their way to the apex of thehydrocyclone where they leave the hydrocyclone through an exit. Theremaining water and other fine particles are removed through an overflowat the top centre of the unit.

In the metallurgical field, a hydrocyclone is used to classify fineparticles according to their size and/or density. For instance a crushedore is conveyed in water to a hydrocyclone where the heavy and/or coarseparticles separated from the fine and/or light rock particles and water.The heavy and/or coarse particles are forced out to the wall of theclassifier by centrifugal force, and these travel along the conical walltowards the apex where they are finally discharged through a spigot. Thefine and/or light particles are removed with most of the water throughan overflow in the centre of the hydrocyclone. The control of separationdepends on the size of the hydrocyclone, the speed and quantity of thewater entering the hydrocyclone inlet, and the amount of vacuum in thehydrocyclone. Such a system is used for dewatering sand and gravelconveyed in a water pipe line. A hydrocyclone is also used forclassifying ground ores into products requiring further processing. Sucha product is one requiring further grinding, and then processing througha hydrocyclone again. Another use of hydrocyclones is desliming ordewatering mineral wastes or tailings to improve consolidationproperties. Another use of a hydrocyclone is for separating fine clayfrom concrete sand. In this latter process, the bulk of the water andthe finer size clay particles flow to the overflow while the largersolid particles of sand with a reduced amount of water are forced to thewall of the hydrocyclone and then discharged through a spigot at theapex.

The control of a hydrocyclone depends on the size and proportion of theunit, the quantity of solids and liquid flowing into the unit, the ratioof water to solids and pressure of the fluid solids mixture entering thehydrocyclone inlet in the form of a slurry feed. The control is alsoeffected by the size of the overflow and apex opening, and the amount ofvacuum in the system. One of the common problems with the hydrocyclonesof today, is to regulate the density of the discharge of solidmaterials. If there is always a constant flow of solid particles in thehydrocyclone feed, then the apex spigot may be adjusted to a particularsize opening and the unit discharges a relatively constant output.However, in the majority of cases, the amount of solids in the slurryfeed varies. The flow of liquid is usually constant, but batches ofsolid particles are deposited into the feed pipe line at frequentintervals. In this situation it is necessary to continually adjust theapex spigot, otherwise excess water tends to escape through the spigotproducing a material which may be unsuitable for further processing.

It is an object of the present invention to provide a simple dischargeregulator for automatically opening and releasing solid particles from ahydrocyclone, and closing when insufficient solid particles are presentthus preventing liquid flushing out of the discharge regulator.

It is a further object of the present invention to provide a method ofrequlating the discharge through an apex spigot of a hydrocyclone so asto control the solids to liquid ratio.

With these and other objects in view, there is provided an automaticdischarge regulator for a discharge exit from a separator or classifiercomprising two sheets of flexible material in side by side relationshipheld together at two opposing edges forming a sleeve, a first end of thesleeve adapted to mate with the discharge exit, a reinforcing pad offlexible material positioned on the outer surface of each of the twosheets such that when the first end of the sleeve mates with thedischarge exit, the second end of the sleeve remains closed with the twosheets touching, the flexible material having sufiicient resilience toallow the second end of the sleeve to be opened and pass solid particlestherethrough.

There is also provided in a method of regulating the discharge of solidmaterials from a separator through an exit including the steps ofcontrolling the velocity and flow of solid particles conveyed in a fluidsuspension to a separator, separating at least a portion of the solidparticles from the fluid and removing the majority of the fluid and anyparticles left therein, the improvement comprising passing the portionof solid particles through a sleeve of resilient material attached tothe exit, the resiliency of the sleeve forcing it closed when no solidparticles pass therethrough, and varying the vacuum inside the separatorto regulate the percent of solid particles separating from the fluid.

With the foregoing objects and features in view and such other objectsand features as may become apparent as this specification proceeds, theinvention will be understood from the following description of apreferred form thereof taken in conjunction with the accompanyingdrawings, which illustrate embodiments of the invention.

FIG. 1 shows a schematic diagram of a hydrocyclone with an automaticdischarge regulator of the present invention.

FIG. 2 shows a side elevation of one type of an automatic dischargeregulator according to the present invention, mounted on a dischargeexit of a separator or classifier.

FIG. 3 shows an end view of the automatic discharge regulator shown inFIG. 2.

FIG. 4 shows a cross-section through the automatic discharge regulatorshown in FIG. 2 at section 4-4.

Referring now to the drawings, in FIG. 1 an automatic discharge controlsystem is shown with a hydrocyclone 10, a tangential or sweep inlet 11entering the hydrocyclone l0, and an overflow pipe 12 leading through aflange connection to a siphon leg 13. An air bleed hose 14 attached tothe siphon leg 13 has a vacuum control valve 15 which is adjustable toallow bleed air into the siphon leg 13 so as to control the vacuuminside the hydrocyclone 10, thereby controlling the opening and closingof an automatic discharge regulator 16 attached to the apex spigot 17 ofthe hydrocyclone 10. The vacuum may also be controlled by varying theelevation of the end of the siphon leg 13.

The regulator shown in FIGS. 2, 3 and 4 comprises two flat rectangularsheets 20 of resilient material. This material is preferably syntheticor natural rubber and is abrasion resistant to stop wear from granularparticles such as sand passing between the two sheets 20. The materialis sufficiently flexible to allow the two sheets 20 to open, but has aconfiguration which always returns the two sheets to their original flatshape thus closing the regulator. Two strips 21 down opposite edges ofthe sheets 20 are adhered together preferably by an adhesive oralternatively by clips or other means, thus forming a passageway 22between the two sheets 20. The regulator fits onto the round exit sleeve23 at the exit of a separator or classifier such as a hydrocyclonesimilar to that shown in FIG. 1 and is attached by a circular clip 24which surrounds a collar 25 of the regulator. The circular clip 24 has anut and bolt 26 which permits its removal, thus permitting a newregulator to be fitted when necessary. The means by which the clip 24 isheld around the collar 25 may be by screw clamps, spring clamps or otherwell known means. The enntrance to the passageway 22 between the sheets20 is circular. However, the two sheets 20 come together into theirflattened position below the exit 23 to form a seal. When no particulatematerial is passing through the exit sleeve 23, the passageway 22 isclosed.

The construction of the regulator is adapted to control the closure. Onthe sheets 20 are two circular pads 27 substantially in the center andon the outside surface of each sheet 20 made from the same material asthe sheets 20 and firmly adhered to the outside surface of each sheetpreferably by an adhesive. A reinforcing strip 28 extending half waydown each sheet 20 is attached to the outside of the sheet preferably byan adhesive. The reinforcing strip 28 has a cut out 29 to allow thereinforcing pad 27 to be carefully placed in the centre of each sheet20. The reinforcing strip 28 and the sheet are attached together attheir top end to form the collar 25. The collar 25 comprises anadditional strip 30 of resilient material similar to the material usedfor the sheet 20 surrounding the inside and outside of the regulator andextending across the top. This gives additional reinforcement to theregulator and also aids at the point where the sheets 20 join to form aprotective collar and stop leakage of liquid or air therethrough.

As may be seen in FIGS. 3 and 4, the reinforcing pads 27 which aid inreturning the sheets 20 to their original flattened state alsosurprisingly cause the ends of the sheets 20 to curve away in a tail 31.This configuration allows the two sheets to touch and seal moredefinitely.

In operation the mixture of liquid and solid particles enter thehydrocyclone 10 through the inlet 11 and primarily due to centrifugalforce, the coarse particles separate and are forced to the conical wallsof the hydrocyclone 10. From this position the particles travel alongthe walls of the hydrocyclone 10 to the automatic discharge regulator 16attached to the apex spigot 17. The vacuum from the siphon leg 13 drawsthe majority of the liquid and any fine particles that remain therein tothe overflow pipe 12. The control is by means of the vacuum controlvalve 15 on the air bleed hose 14. The remaining coarse solid particlestravel to the regulator and because they are denser and heavier than theliquid, they force the two sheets 20 apart and pass through thepassageway 22. It has been found that with this type of regulator theliquid content of the apex discharge can be dependably regulated asdesired. One means of controlling the ratio or mixture of solids andliquids flowing through this regulator is carried out by means of thevacuum control valve 15. Thus if too much liquid is discharging throughthe regulator with the solid particles then the vacuum inside thehydrocyclone is increased by reducing the air bled into the siphon leg13. If too many coarse particles are discharging through the overflowpipe 12 then the vacuum is decreased by increasing the air bled into thesiphon leg 13. When the particles are no longer conveyed into thehydrocyclone 10 while the flow of liquid still continues, then thepassageway 22 closes and the liquid discharges through the overflow pipe12.

In the case of hydrocyclone being utilized as a classifier, theproportion of solids discharging through the apex spigot may beregulated by a number of different ways. First of all there is a controlon the percentage of solids that are conveyed by the liquid, secondlythe volume of liquid entering the hydrocyclone may be controlled,thirdly the pressure, hence the velocity of liquid can also becontrolled and fourthly the preferred form of control is the amount ofvacuum in the system. Other possible variations include the inletdiameter together with the diameter of the overflow l2 and the apexspigot 17. The solids can generally be classified as to size or density.However, when size is mentioned one must also be aware of the shape ofthe particles, for instance, flaky material with a large surface areatends to stay with the liquid and is more difficult to separate thancoarse granular particles. The adjustment of the regulator is generallymade on site, adjusting the vacuum flow and velocity of liquid enteringthe hydrocyclone such that there is barely any liquid discharging fromthe regulator when the unit is operating only on a liquid, then byslowly adding solid particles to the liquid entering the hydrocycloneand again further adjustment made to the vacuum so that a minimum ofliquid discharges with the solid particles. If it is found that too manycoarse particles are passing through the overflow pipe, then adjustmentmust be made again to achieve the maximum solid discharge through theregulator.

In one particular embodiment the automatic discharge regulator was madefrom a natural rubber material known as Linatex (registered trade mark).The two sheets 20 were each Va inch thick and the two pads 27 were each54 inch thick. The width of the sheets 20 was I 1% inches and theirlength was 17 inches and a strong rubber adhesive was used on each strip21 to join the two sheets 20 together and on each pad 27 to adhere it tothe sheet 20. These pads 27 were each 8 inches in diameter. Reinforcingstrips 28 and a collar were added to the automatic discharge regulatorand the unit was attached to the apex spigot of the hydrocyclone. Thehydrocyclone was first tested with only water fed into the unitjand thevacuum control adjusted such that no water escaped through the automaticdischarge regulator. Then as the sand and clay were added to thefeedwater, it was found that the sand separated and discharged throughthe regulator whereas most of the clay and water discharged through theoverflow.

It will be apparent to those skilled in the art that a number ofvariations may be made without departing from the scope of the presentinvention. For instance, the pads 27 need not necessarily be circular,they may be joined to the reinforcing strips 28, alternatively they maybe oval or diamond in shape and the sheets need not necessarily beexactly rectangular. In some instances where it is necessary to separatedifferent grades of ore from a liquid, then several classifiers may beused with the conditions inside the classifiers adjusted so thatdifferent size particles separate in different classifiers. The devicemay be constructed from plain sheets of flexible material such as rubberor may be specially moulded. The materials used for the regulator mustbe selected to suit the particular conditions including the ambienttemperature and the type of material passing through the regulator.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. An automatic discharge regulator for a discharge exit from aseparator or a classifier comprising a sleeve comprised of two sheets ofresilient flexible material in side by side relationship, abutting oneanother at one end and adapted to sealingly mate with the discharge exitat the other end, said two sheets being sealingly held together alongthe length of the two opposing edges thereof, two reinforcing pads offlexible, elastic material, respectively, centrally located on andfixedly attached only to the outer surface of each of said two sheets sothat each of said two sheets longitudinally extend in the direction ofsaid one end beyond the corresponding said reinforcing pad, saidreinforcing pads aiding in resiliently retaining said sheets at said oneend in abutting relationship, thereby closing said one end of saidsleeve when said regulator is in mating engagement with the dischargeexit, the flexible material of said two sheets and of said reinforcingpads having sufficient resilience to allow said one end of said sleeveto be opened by and pass solid particles therethrough.

2. The automatic discharge regulator according to claim 1 wherein thesheets of flexible material are rectangular and the reinforcing pad oneach sheet is circular.

3. In a method of regulating the discharge of solid materials from aseparator through an exit including the steps of controlling thevelocity and flow of solid particles conveyed in a fluid suspension to aseparator, separating at least a portion of the solid particles from thefluid, and removing the majority of the fluid and any particles lefttherein, the improvement comprising passing the portion of solidparticles through a sleeve of resilient material attached to the exit,the resiliency of 6 the sleeve forcing it closed when no solid particlespass therethrough, and varying the vacuum inside the separator toregulate the percent of solid particles separating from the fluid.

4. A method of regulating the discharge of solid particles from ahydrocyclone comprising the steps of conveying a slurry of the solidparticles in a liquid to the hydrocyclone, separating at least a portionof the solid particles from the liquid within the hydrocyclone,discharging the portion of the solid particles through a sleeve ofresilient material attached to an exit spigot of the hydrocyclone, theresiliency of the material forming the sleeve closed when no solidparticles pass therethrough, and varying the vacuum in the hydrocycloneto hold the sleeve closed when no solid particles pass therethrough andregulate the percent of solid particles separating from the liquid.

5. The method of regulating the discharge of solid particles from ahydrocyclone according to claim 4 wherein the vacuum in the hydrocycloneis regulated by varying air bled into a siphon leg from an overflow pipeof the hydrocyclone.

6. An automatic discharge regulator for a discharge exit from aseparator or a classifier comprising a sleeve comprised of two sheets ofresilient flexible material in side by side relationship, abutting oneanother at one end and adapted to sealingly mate with the discharge exitat the other end, said two sheets being sealingly held together alongthe length of the two opposing edges thereof, two reinforcing pads offlexible, elastic material, respectively, centrally located on andfixedly attached only to the outer surface of each of said two sheets,said reinforcing pads aiding in resiliently retaining said sheets atsaid one end in abutting relationship, thereby closing said one end ofsaid sleeve when said regulator is in mating engagement with thedischarge exit, the other end of the sleeve having a reinforced collarof flexible material, the flexible material of said two sheets and ofsaid reinforcing pads having sufficient resilience to allow said one endof said sleeve to be opened by and pass solid particles therethrough;and

said regulator further comprising a reinforcing strip extending fromsaid other end of said sleeve in outer coaxial abutting relationshipwith said two sheets and terminating at a location spaced from theclosure of said one end.

7. The automatic dishcarge regulator of claim 6, wherein said sheets arerectangular, said reinforcing pad on each sheet is circular, and saidreinforcing strip partially surrounds, but is spaced from, saidreinforcing pad.

8. The automatic discharge regulator of claim 6 wherein the two sheetsof flexible material are resilient natural rubber and are held togetherat two opposing edges by rubber adhesive, and where the reinforcing padsare natural rubber and are positioned on the outside surface of thesheets by a rubber adhesive.

1. An automatic discharge regulator for a discharge exit from aseparator or a classifier comprising a sleeve comprised of two sheets ofresilient flexible material in side by side relationship, abutting oneanother at one end and adapted to sealingly mate with the discharge exitat the other end, said two sheets being sealingly held together alongthe length of the two opposing edges thereof, two reinforcing pads offlexible, elastic material, respectively, centrally located on andfixedly attached only to the outer surface of each of said two sheets sothat each of said two sheets longitudinally extend in the direction ofsaid one end beyond the corresponding said reinforcing pad, saidreinforcing pads aiding in resiliently retaining said sheets at said oneend in abutting relationship, thereby closing said one end of saidsleeve when said regulator is in mating engagement with the dischargeexit, the flexible material of said two sheets and of said reinforcingpads having sufficient resilience to allow said one end of said sleeveto be opened by and pass solid particles therethrough.
 2. The automaticdischarge regulator according to claim 1 wherein the sheets of flexiblematerial are rectangular and the reinforcing pad on each sheet iscircular.
 3. In a method of regulating the discharge of solid materialsfrom a separator through an exit including the steps of controlling thevelocity and flow of solid particles conveyed in a fluid suspension to aseparator, separating at least a portion of the solid particles from thefluid, and removing the majority of the fluid and any particles lefttherein, the improvement comprising passing the portion of solidparticles through a sleeve of resilient material attached to the exit,the resiliency of the sleeve forcing it closed when no solid particlespass therethrough, and varying the vacuum inside the separator toregulate the percent of solid particles separating from the fluid.
 4. Amethod of regulating the discharge of solid particles from ahydrocyclone comprising the steps of conveying a slurry of the solidparticles in a liquid to the hydrocyclone, separating at least a portionof the solid particles from the liquid within the hydrocyclone,discharging the portion of the solid particles through a sleeve ofresilient material attached to an exit spigot of the hydrocyclone, theresiliency of the material forming the sleeve closed when no solidparticles pass therethrough, and varying the vacuum in the hydrocycloneto hold the sleeve closed when no solid particles pass therethrough andregulate the percent of solid particles separating from the liquid. 5.The method of regulating the discharge of solid particles from ahydrocyclone according to claim 4 wherein the vacuum in the hydrocycloneis regulated by varying air bled into a siphon leg from an overflow pipeof the hydrocyclonE.
 6. An automatic discharge regulator for a dischargeexit from a separator or a classifier comprising a sleeve comprised oftwo sheets of resilient flexible material in side by side relationship,abutting one another at one end and adapted to sealingly mate with thedischarge exit at the other end, said two sheets being sealingly heldtogether along the length of the two opposing edges thereof, tworeinforcing pads of flexible, elastic material, respectively, centrallylocated on and fixedly attached only to the outer surface of each ofsaid two sheets, said reinforcing pads aiding in resiliently retainingsaid sheets at said one end in abutting relationship, thereby closingsaid one end of said sleeve when said regulator is in mating engagementwith the discharge exit, the other end of the sleeve having a reinforcedcollar of flexible material, the flexible material of said two sheetsand of said reinforcing pads having sufficient resilience to allow saidone end of said sleeve to be opened by and pass solid particlestherethrough; and said regulator further comprising a reinforcing stripextending from said other end of said sleeve in outer coaxial abuttingrelationship with said two sheets and terminating at a location spacedfrom the closure of said one end.
 7. The automatic dishcarge regulatorof claim 6, wherein said sheets are rectangular, said reinforcing pad oneach sheet is circular, and said reinforcing strip partially surrounds,but is spaced from, said reinforcing pad.
 8. The automatic dischargeregulator of claim 6 wherein the two sheets of flexible material areresilient natural rubber and are held together at two opposing edges byrubber adhesive, and where the reinforcing pads are natural rubber andare positioned on the outside surface of the sheets by a rubberadhesive.